Silica gel promoted environment-friendly synthesis of α-amino amidines and regioselective transformation of α-amino amidines into amidino substituted indazoles
作者:A. Sagar、Venkata Nagarjuna Babu、Duddu. S. Sharada
DOI:10.1039/c5ra02491a
日期:——
Ugi-type strategy (U-3CR) for the synthesis of a wide variety of α-amino amidines has been developed by using silica gel as promoter, and a novel access to amidino substituted indazoles in a regioselective manner is presented via iron(III) catalyzed post Ugi cyclization strategy. This method allows an easy construction of amidino substituted indazoles in good yields with broad substrate scope starting from
A facile and efficient synthetic protocol for the synthesis of alpha-amino amidines has been developed using a molecular iodine-catalyzed three-component coupling reaction of isocyanides, amines, and aldehydes. The presented strategy offers the advantages of mild reaction conditions, low environmental impact, clean and simple methodology, high atom economy, wide substrate scope and high yields.
Solvent Dependent Competitive Mechanisms for the Ugi Multicomponent Reaction: A Joint Theoretical and Experimental Study in the α-Acyl Aminocarboxamides vs α-Amino Amidines Formation
作者:Marcelo H. R. Carvalho、João P. R. S. Ribeiro、Pedro P. De Castro、Saulo T. A. Passos、Brenno A. D. Neto、Hélio F. Dos Santos、Giovanni W. Amarante
DOI:10.1021/acs.joc.2c01272
日期:2022.8.19
these two possible products was tuned by simple modifications of the reaction conditions. A broad scope is presented, allowing access to the desired products in up to 87% (Ugi adduct) and 93% (α-amino amidine). Theoretical calculations were carried out, and the analysis led to the proposal of a new mechanistic pathway for the Ugireaction, in which methanol acts not only as the solvent but also as a reagent
提出了一种制备α-酰基氨基甲酰胺和α-氨基脒的合成方案。通过对反应条件的简单修改来调整对这两种可能产物的选择性。提供了广泛的范围,允许获得高达 87%(Ugi 加合物)和 93%(α-氨基脒)的所需产品。进行了理论计算,分析导致提出了 Ugi 反应的新机制途径,其中甲醇不仅充当溶剂,还充当试剂。高分辨率(串联)质谱实验允许检测和表征与这种新的替代反应途径相关的关键中间体,从而支持理论建议。